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.Dd May  1, 2006
.Dt KRB5_VERIFY_USER 3
.Os HEIMDAL
.Sh NAME
.Nm krb5_verify_user ,
.Nm krb5_verify_user_lrealm ,
.Nm krb5_verify_user_opt ,
.Nm krb5_verify_opt_init ,
.Nm krb5_verify_opt_alloc ,
.Nm krb5_verify_opt_free ,
.Nm krb5_verify_opt_set_ccache ,
.Nm krb5_verify_opt_set_flags ,
.Nm krb5_verify_opt_set_service ,
.Nm krb5_verify_opt_set_secure ,
.Nm krb5_verify_opt_set_keytab
.Nd Heimdal password verifying functions
.Sh LIBRARY
Kerberos 5 Library (libkrb5, -lkrb5)
.Sh SYNOPSIS
.In krb5.h
.Ft krb5_error_code
.Fn "krb5_verify_user" "krb5_context context" " krb5_principal principal" "krb5_ccache ccache" "const char *password" "krb5_boolean secure" "const char *service"
.Ft krb5_error_code
.Fn "krb5_verify_user_lrealm" "krb5_context context" "krb5_principal principal" "krb5_ccache ccache" "const char *password" "krb5_boolean secure" "const char *service"
.Ft void
.Fn krb5_verify_opt_init "krb5_verify_opt *opt"
.Ft void
.Fn krb5_verify_opt_alloc "krb5_verify_opt **opt"
.Ft void
.Fn krb5_verify_opt_free "krb5_verify_opt *opt"
.Ft void
.Fn krb5_verify_opt_set_ccache "krb5_verify_opt *opt" "krb5_ccache ccache"
.Ft void
.Fn krb5_verify_opt_set_keytab "krb5_verify_opt *opt" "krb5_keytab keytab"
.Ft void
.Fn krb5_verify_opt_set_secure "krb5_verify_opt *opt" "krb5_boolean secure"
.Ft void
.Fn krb5_verify_opt_set_service "krb5_verify_opt *opt" "const char *service"
.Ft void
.Fn krb5_verify_opt_set_flags "krb5_verify_opt *opt" "unsigned int flags"
.Ft krb5_error_code
.Fo krb5_verify_user_opt
.Fa "krb5_context context"
.Fa "krb5_principal principal"
.Fa "const char *password"
.Fa "krb5_verify_opt *opt"
.Fc
.Sh DESCRIPTION
The
.Nm krb5_verify_user
function verifies the password supplied by a user.
The principal whose password will be verified is specified in
.Fa principal .
New tickets will be obtained as a side-effect and stored in
.Fa ccache
(if
.Dv NULL ,
the default ccache is used).
.Fn krb5_verify_user
will call
.Fn krb5_cc_initialize
on the given
.Fa ccache ,
so
.Fa ccache
must only initialized with
.Fn krb5_cc_resolve
or
.Fn krb5_cc_gen_new .
If the password is not supplied in
.Fa password
(and is given as
.Dv NULL )
the user will be prompted for it.
If
.Fa secure
the ticket will be verified against the locally stored service key
.Fa service
(by default
.Ql host
if given as
.Dv NULL
).
.Pp
The
.Fn krb5_verify_user_lrealm
function does the same, except that it ignores the realm in
.Fa principal
and tries all the local realms (see
.Xr krb5.conf 5 ) .
After a successful return, the principal is set to the authenticated
realm. If the call fails, the principal will not be meaningful, and
should only be freed with
.Xr krb5_free_principal 3 .
.Pp
.Fn krb5_verify_opt_alloc
and
.Fn krb5_verify_opt_free
allocates and frees a
.Li krb5_verify_opt .
You should use the the alloc and free function instead of allocation
the structure yourself, this is because in a future release the
structure wont be exported.
.Pp
.Fn krb5_verify_opt_init
resets all opt to default values.
.Pp
None of the krb5_verify_opt_set function makes a copy of the data
structure that they are called with. It's up the caller to free them
after the
.Fn krb5_verify_user_opt
is called.
.Pp
.Fn krb5_verify_opt_set_ccache
sets the
.Fa ccache
that user of
.Fa opt
will use. If not set, the default credential cache will be used.
.Pp
.Fn krb5_verify_opt_set_keytab
sets the
.Fa keytab
that user of
.Fa opt
will use. If not set, the default keytab will be used.
.Pp
.Fn krb5_verify_opt_set_secure
if
.Fa secure
if true, the password verification will require that the ticket will
be verified against the locally stored service key. If not set,
default value is true.
.Pp
.Fn krb5_verify_opt_set_service
sets the
.Fa service
principal that user of
.Fa opt
will use. If not set, the
.Ql host
service will be used.
.Pp
.Fn krb5_verify_opt_set_flags
sets
.Fa flags
that user of
.Fa opt
will use.
If the flag
.Dv KRB5_VERIFY_LREALMS
is used, the
.Fa principal
will be modified like
.Fn krb5_verify_user_lrealm
modifies it.
.Pp
.Fn krb5_verify_user_opt
function verifies the
.Fa password
supplied by a user.
The principal whose password will be verified is specified in
.Fa principal .
Options the to the verification process is pass in in
.Fa opt .
.Sh EXAMPLES
Here is a example program that verifies a password. it uses the
.Ql host/`hostname`
service principal in
.Pa krb5.keytab .
.Bd -literal
#include <krb5.h>

int
main(int argc, char **argv)
{
    char *user;
    krb5_error_code error;
    krb5_principal princ;
    krb5_context context;

    if (argc != 2)
	errx(1, "usage: verify_passwd <principal-name>");

    user = argv[1];

    if (krb5_init_context(&context) < 0)
	errx(1, "krb5_init_context");

    if ((error = krb5_parse_name(context, user, &princ)) != 0)
	krb5_err(context, 1, error, "krb5_parse_name");

    error = krb5_verify_user(context, princ, NULL, NULL, TRUE, NULL);
    if (error)
        krb5_err(context, 1, error, "krb5_verify_user");

    return 0;
}
.Ed
.Sh SEE ALSO
.Xr krb5_cc_gen_new 3 ,
.Xr krb5_cc_initialize 3 ,
.Xr krb5_cc_resolve 3 ,
.Xr krb5_err 3 ,
.Xr krb5_free_principal 3 ,
.Xr krb5_init_context 3 ,
.Xr krb5_kt_default 3 ,
.Xr krb5.conf 5
